[mms6]

Hi there Head Fi boyz and galz
 
I was toggling through my closet and found a pair of Sony MDR-NC7 headphones..
 
I opened the carrying pouch containing the Sony Noise Cancelling NC7 headphones and found an Airplane adapter. (the one 3.5mm stereo to 2x 3.5mm mono jack converter)
 
I decided to use the airplane adapter on my AKG K240 mkII, and realized that it boosts the bass response over the overall music without killing the overall volume that much....
 
I also tried it with my AKG K701 and realized that is boosts bass response and it is much more present and punchy, but the mids and highs are also clear without distortion to the original sound of the K701s... Although the K701 overall volume from the same source with the same volume level has been bit more quiet when compared to the K240 mkII.....
 
Now, most of the times, I use this airplane adapter thingy to boost bass on bass light phones without an amp's bulkiness (well depending on headphone really since my K701s are not as loud when used with the adapter jack...)
 
 
 
Does anyone realize and can explain this phenomenon?
 
Thanks.

 

[ssrock64]

I'll bump this here. It sounds like an ill-designed product to me, but there may be some good forces at work here.
 
Do you have good ears to spot if any FLAC files or anything are being compromised?

 

[mms6]

I don't think so.. The FLAC file I used with both headphones with and without the adapter is the same. I also tried to use the retail CDs and found the same bass boost...
 
I am running it on my ASUS G74SX laptop with ASUS Xonar U3 with a Fiio E10 amp and the headphones tested at my K240 mkII and K701.
 
I also have tested the airplane adapter with the AKG 240 mkII and K701 straight to my iPod touch 4G, and same bass boost (songs are in MP3 320 kbps and are different to the songs used on my laptop)
 
 
I do not know if I experience this only with AKG headphones or not...
 
I actually also tried my Sony MDR-NC7s which this came with, and to my surprise, a very "big" noticable bass boost when the Noise Cancelling is switched to on with the airplane connector connected.
 
With the AKG phones, there is a increase in bass, but not as a big increase in bass boost when compared to the Sony MDR-NC7....

 

[ssrock64]

Perhaps you should try posting this in the sound science forum and see if anyone can figure it out over there. Keep us posted!

 

[Mad Dude]

Do you have a multimeter? If yes, you could try to measure the impedance (Ohms) on this adaptor. Perhaps there are resistors in it (for whatever reason) - this could produce an change in the sound as you describe it.

 

[Lurkumaural]

If there's a bass boost, it's possible that the adapter's impedance is different (lower?  IDK) in the bass frequencies than the rest of the spectrum.  Or, cracking it open may reveal not simply a resistor network but a low-pass filter.

 

[mms6]

The adapter has 2 philips screw holding it together.
 
I will take it apart tomorrow and see its internals...
 
Thanks for the tip

 

[ssrock64]

Tell us what you find!